Intravenous (IV) access is the single most frequently performed invasive medical procedure in the world today. Though IV is generally considered routine, there are a number of situations in which inhibited IV access can be painful, traumatic, or even dangerous to patients. These include conditions in which subcutaneous blood vessels are difficult to locate because of patient characteristics or environmental conditions. For example, in battlefield conditions, where lighting is limited, it may be difficult, if not impossible, to locate subsurface blood vessels for injection. Easy IV access is especially critical in emergency situations in which a patient's life may depend on immediate IV access and “first-stick” accuracy.
Medical practitioners often encounter difficulty in gaining IV access in a significant portion of the patient population for which subsurface blood vessels are obscured. Such patients include obese patients, darkly pigmented patients, neonates (infants from birth to four weeks of age), children under four years of age, patients experiencing lowered blood pressure, patients who have collapsed veins, and patients requiring IV access in a minor or obscured blood vessel. Difficulties arising in these populations are demonstrated by the numbers: first-stick success rates in children and infants are currently 30%, which indicates that for 70% of the time, IV access in these populations requires more than one stick attempt. In neonates, more than 90% of IV catheters must be removed prematurely, mainly because of the improper placement of the catheters. Difficulties with IV access are encountered not only in locating the subsurface blood vessels, but also in complications that arise from improper insertion of needles or catheters in target blood vessels. Such complications include infiltration, thrombophlebitis, and infection of the IV access site.
It should be noted that children who have obscured blood vessels might lie in operating rooms for longer than 30 minutes, while medical practitioners attempt to find a blood vessel suitable for successful IV access. With the cost of operating room time approximately $14,000 per hour, delayed IV access can significantly increase the expense of both operating and office-based medical procedures.
IV access is especially critical in emergency situations when first stick accuracy can be life saving. A loss of time or inability to obtain IV access can mean the difference between life and death or, at a minimum, cause significant physical and psychological trauma. Further complicating matters, loss of patient blood and blood pressure in trauma situations can make locating subsurface blood vessels extremely difficult.
In cases where catheters, cannulas, and/or IV drips are used in patient treatment, these devices typically remain in a patient's blood vessel for a long period of time. However, in order to prevent infection, the devices are generally relocated to new body areas every 48 to 72 hours. Constant relocation of these devices over a long-term hospital stay may result in a need for medical practitioners to access less-optimal blood vessels, after more prominent blood vessels have been used. Often, these less prominent blood vessels can not easily be found by visual and tactile clues, and accessing them may require multiple sticks to the patient, which thereby causes the patient physical and emotional pain and trauma. Inhibited IV access can also subject medical practitioners to legal liability risk, by contributing to the complications associated with improper, ineffective, or delayed IV access.
IV location and access is both a visual and a tactile process. Traditional methods of IV location and access rely on the medical practitioner using his/her eyes and both hands to clean the target area, apply a tourniquet, locate the blood vessel by palpating the target area, and apply the hypodermic needle. For the sake of safe and efficient patient treatment, it is critical that the hands and eyes of the medical practitioner gaining IV access not be hindered in any way.
Medical practitioners gain proficiency at IV location and access through a process of learning and continued practice. To ensure a high standard of healthcare and patient safety, it is imperative that medical practitioners do not attempt to gain IV access before they are adequately trained. Unfortunately, traditional methods of IV location and access may require years of trial-and-error practice and thereby delay critical healthcare, which increases healthcare costs and possibly jeopardizes patient health. Any advancement in healthcare practices that reduces the amount of training time required for proficiency in gaining skill at IV access could contribute significantly to improved patient care.
In order to provide the highest standard of care while reducing the cost of healthcare, it is imperative that medical practitioners locate and gain access to subsurface blood vessels in a rapid and accurate manner. Simplified IV location and access can help to save lives in emergency situations, avoid the trauma of multiple sticks in situations in which patients' vessels are difficult to locate, reduce the number of complications that stem from improperly inserted hypodermic needles and IVs, and reduce costs of medical procedures, by speeding up a critical bottleneck in many medical procedures: IV access. Therefore, what is needed is a hands-free device that allows medical practitioners to rapidly and accurately locate subsurface blood vessels for IV access.
As of late, apparatus have developed that help medical personnel more accurately locate blood vessels. For example a system and method for locating subcutaneous blood vessels via IR enhancement is described in U.S. Pat. No. 4,817,622, entitled, “Infrared imager for viewing subcutaneous location of vascular structures and method of use,” in which a human appendage, typically the inside of the elbow, is illuminated with an IR source, for example, at least one incandescent light bulb. A video camera for producing a video image and immediately overlying monitor for displaying the video image is utilized to look at the flesh. The camera is sensitive to IR radiation. A video display in which IR absorbing or scattering contrasting portions of the flesh are highlighted, for example, hard-to-find veins for inserting needles. A contrast enhancing circuit is included, which discloses amplifying the video information with high contrast enhancement of the video. Adaptation of the disclosed circuit to conventional TV charge coupled device cameras and monitors is illustrated with compensation of horizontal sweep to even image background, intensity averaging line-to-line for vertical image uniformity, and display of image contrasts, in a log amplification format. While the '622 patent describes an IR blood vessel viewer, the '622 patent utilizes an analog signal processor, which is not adequate for supporting the digital algorithms needed for true image enhancement and visualization.
More recently, U.S. Pat. No. 5,519,208, purports to describes a method and apparatus for gaining intravenous access that includes a source of radiation for irradiating an area of the patient with radiation having a wavelength that is absorbed in areas containing veins and reflected in all other areas. The reflected radiation is then read and the output displayed. Using this technique, venous structures appear as dark lines on the display, enabling a user to position the tip of a hypodermic needle at an appropriate location for drawing blood.
Along similar lines, U.S. Pat. No. 6,032,070, purports to describe a system and method to view an anatomical structure such as a blood vessel in high contrast with its surrounding tissue. The system and method may be used to produce an image of an anatomical structure using reflected electromagnetic radiation singularly scattered from target tissue. The system and method purport to provide improved contrast between any anatomical structure and its surrounding tissue for use in any imaging system.
Likewise, U.S. Pat. No. 6,230,046, purportedly discloses a system and method for enhancing visualization of veins, arteries or other subcutaneous natural or foreign structures of the body and for facilitating intravenous insertion or extraction of fluids, medication or the like in the administration of medical treatment to human or animal subjects. The system and method include a light source for illuminating or transilluminating the corresponding portion of the body with light of a selected wavelengths and a low-level light detector such as night vision goggles, a photomultiplier tube, photodiode or charge coupled device for generating an image of the illuminated body portion, and optical filter(s) of selected spectral transmittance which can be located at the light source(s), detector, or both.
The above referenced patents are illustrative of attempts to demarcate blood vessels from surrounding tissue. The systems and methods of the described patents are non-invasive and, most importantly, provide the near “real time” visualization of the image necessary for these devices to serve their practical purpose. However, because of the need to provide near “real time” images, these devices primarily depend on raw images, or images marginally enhanced by traditional analog means, which are of relatively poor quality for venepuncture accuracy. Therefore, there is a need not only for a device for visualizing subsurface blood vessels, but also a system and method for vascular image location, image enhancement, and hands-free manipulation, for quick and accurate IV access.
Therefore, there is a need for an improved system and method for locating and accessing a target blood vessel that that has the vein enhancing features of the prior art devices discussed above, but produces high quality images in near “real time” such that the system may be used by medical personnel during venepuncture, that allows target blood vessels to be more accurately and rapidly located than is possible using current systems and methods, that allows target blood vessels to be more easily located in difficult conditions and body types (e.g., obese patients, dark pigmentation skin, neonates, collapsed veins, low lighting), that reduces patient pain and trauma, both emotionally and physically; and that allows minimally trained medical staff to provide IV access.